Multi-beam CSI feedback

Abstract

In multi-beam communication, the UE may assist in the scheduling of beams utilized during the multi-beam communication by improving the manner in which the quality of the beam is reported to the network. The apparatus may measure a signal received from a base station on at least one beam. The apparatus may detect a triggering event for providing CSI for the at least one beam. The apparatus may transmit an uplink transmission comprising a CSI report in response to detecting the triggering event. The apparatus may receive an uplink request from a UE for providing CSI for at least one beam. The apparatus may transmit an indication scheduling a CSI report in response to the uplink request. The apparatus may receive an uplink transmission from the UE comprising the CSI report for the at least one beam.

What is claimed is: 
     
       1. A method of wireless communication performed by a user equipment (UE), comprising:
 measuring a signal received from a base station via a beam; 
 detecting a triggering event for providing channel state information (CSI) for the beam, wherein the triggering event comprises a beam failure; 
 sending an uplink request based on the triggering event to reserve uplink resources for reporting of the CSI, wherein the uplink request is sent via a scheduling request (SR) for which selection of a physical uplink control channel (PUCCH) resource on which the SR is sent indicates that the beam is associated with an occurrence of the triggering event; 
 receiving an indication scheduling a CSI report in response to the uplink request; and 
 transmitting an uplink transmission comprising the CSI report in response to detecting the triggering event, wherein the CSI report is transmitted according to the indication. 
 
     
     
       2. The method of  claim 1 , wherein detecting the triggering event comprises detecting that a measurement of the signal meets a threshold. 
     
     
       3. The method of  claim 1 , wherein detecting the triggering event comprises detecting that at least one of a reference signal received power (RSRP) or a channel quality indicator (CQI) is below a threshold. 
     
     
       4. The method of  claim 1 , wherein the indication comprises an uplink grant and the CSI report comprises a medium access control-control element (MAC-CE). 
     
     
       5. The method of  claim 1 , wherein the CSI report comprises an indication of a recommended beam. 
     
     
       6. The method of  claim 1 , wherein the triggering event is detected based on the measuring the signal. 
     
     
       7. The method of  claim 1 , wherein the transmitting comprises transmitting, to the base station, on a plurality of uplink transmission configuration indicator (TCI) beams via a physical uplink control channel (PUCCH), the CSI report, and wherein a first uplink TCI beam of the plurality of uplink TCI beams corresponds to the beam from which the signal is received. 
     
     
       8. The method of  claim 7 , wherein the CSI report comprises information of each of the plurality of uplink TCI beams, wherein the information indicates the first uplink TCI beam is associated with the beam failure. 
     
     
       9. The method of  claim 7 , further comprising receiving, from the base station, instructions for the UE to change at least one of the plurality of uplink TCI beams based on the uplink transmission from the UE. 
     
     
       10. The method of  claim 1 , wherein the beam from which the signal is received from the base station is a first downlink beam, wherein the uplink transmission is transmitted on an uplink beam that corresponds to a second downlink beam different from the first downlink beam, and wherein selection of the uplink beam implicitly indicates to the base station that the first downlink beam is associated with the occurrence of the triggering event. 
     
     
       11. The method of  claim 1 , further comprising receiving, from the base station, a downlink control signal comprising an indication in a medium access control-control element (MAC-CE) of the downlink control signal, the indication indicating activation of one or more new beams based on the occurrence of the triggering event. 
     
     
       12. The method of  claim 1 , further comprising receiving, from the base station, an uplink grant indicating allocation of uplink resources for each of a plurality of uplink beams, wherein the uplink resources of each of the plurality of uplink beams includes a particular time-frequency resource that corresponds to a unique triggering event, wherein the uplink transmission is transmitted using the particular time-frequency resource that corresponds to the detected triggering event and implicitly indicates to the base station the occurrence of the triggering event. 
     
     
       13. The method of  claim 1 , further comprising receiving, from the base station, an uplink grant indicating allocation of uplink resources for each of a plurality of uplink beams, wherein the uplink resources of each of the plurality of uplink beams includes a plurality of carrier frequencies that each respectively correspond to a unique triggering event, wherein the uplink transmission is transmitted using a particular carrier frequency of the plurality of carrier frequencies that corresponds to the detected triggering event and implicitly indicates to the base station the occurrence of the triggering event. 
     
     
       14. The method of  claim 1 , wherein the uplink request is mapped to the SR, wherein the SR is transmitted using multiple PUCCH resource identifiers. 
     
     
       15. The method of  claim 1 , wherein the SR is a first SR, wherein the uplink request is mapped to multiple SRs including the first SR, and wherein each of the multiple SRs uses a same PUCCH resource identifier. 
     
     
       16. An apparatus for wireless communication at a user equipment (UE), the apparatus comprising:
 a transceiver; 
 one or more memories, individually or in combination, having instructions; and 
 one or more processors, individually or in combination, configured to execute the instructions and cause the apparatus to:
 measure a signal received via a beam from a base station, the signal received via the transceiver; 
 detect a triggering event for providing channel state information (CSI) for the beam, wherein the triggering event comprises a beam failure; 
 send, via the transceiver an uplink request based on the triggering event to reserve uplink resources for reporting of the CSI, wherein the uplink request is sent via a scheduling request (SR) for which selection of a physical uplink control channel (PUCCH) resource on which the SR is sent indicates that the beam is associated with an occurrence of the triggering event; 
 receive, via the transceiver, an indication scheduling a CSI report in response to the uplink request; and 
 transmit, via the transceiver, an uplink transmission comprising the CSI report in response to detecting the triggering event, wherein the CSI report is transmitted according to the indication. 
 
 
     
     
       17. The apparatus of  claim 16 , wherein the one or more processors, being configured to detect the triggering event, are further configured to detect that a measurement of the signal meets a threshold. 
     
     
       18. The apparatus of  claim 16 , wherein the one or more processors, being configured to detect the triggering event, are further configured to detect that at least one of a reference signal received power (RSRP) or a channel quality indicator (CQI) is below a threshold. 
     
     
       19. The apparatus of  claim 16 , wherein the indication comprises an uplink grant and the CSI report comprises a medium access control-control element (MAC-CE). 
     
     
       20. The apparatus of  claim 16 , wherein the CSI report comprises an indication of a recommended beam. 
     
     
       21. The apparatus of  claim 16 , wherein the triggering event is detected based on the signal measurement. 
     
     
       22. The apparatus of  claim 16 , wherein the one or more processors, being configured to transmit the uplink transmission, are further configured to transmit, to the base station, on a plurality of uplink transmission configuration indicator (TCI) beams via a physical uplink control channel (PUCCH), the CSI report, and wherein a first uplink TCI beam of the plurality of uplink TCI beams corresponds to the beam from which the signal is received. 
     
     
       23. The apparatus of  claim 22 , wherein the CSI report comprises information of each of the plurality of uplink TCI beams, wherein the information indicates the first uplink TCI beam is associated with the beam failure. 
     
     
       24. The apparatus of  claim 22 , wherein the one or more processors are further configured to receive, from the base station via the transceiver, instructions for the UE to change at least one of the plurality of uplink TCI beams based on the uplink transmission from the UE. 
     
     
       25. The apparatus of  claim 16 , wherein the uplink request is mapped to the SR, wherein the SR is transmitted using multiple PUCCH resource identifiers. 
     
     
       26. The apparatus of  claim 16 , wherein the SR is a first SR, wherein the uplink request is mapped to multiple SRs including the first SR, and wherein each of the multiple SRs uses a same PUCCH resource identifier. 
     
     
       27. A method of wireless communication performed by a base station, the method comprising:
 receiving an uplink request from a user equipment (UE) for providing channel state information (CSI) for a beam, wherein the uplink request is received via a scheduling request (SR) for which selection of a physical uplink control channel (PUCCH) resource on which the SR is received indicates that the beam is associated with an occurrence of a triggering event, wherein the triggering event comprises a beam failure; 
 transmitting an indication scheduling a CSI report in response to the uplink request; and 
 receiving an uplink transmission from the UE comprising the CSI report for the beam wherein the CSI report is received according to the indication. 
 
     
     
       28. The method of  claim 27 , wherein the indication comprises an uplink grant and the CSI report comprises a medium access control-control element (MAC-CE). 
     
     
       29. An apparatus for wireless communication at a base station, the apparatus comprising:
 a transceiver; 
 one or more memories, individually or in combination, having instructions; and 
 one or more processors, individually or in combination, configured to execute the instructions and cause the apparatus to:
 receive, via the transceiver, an uplink request from a user equipment (UE) for providing channel state information (CSI) for a beam, wherein the uplink request is received via a scheduling request (SR) for which selection of a physical uplink control channel (PUCCH) resource on which the SR is received indicates that the beam is associated with an occurrence of a triggering event, wherein the triggering event comprises a beam failure; 
 transmitting, via the transceiver, an indication scheduling a CSI report in response to the uplink request; and 
 receiving, via the transceiver, an uplink transmission from the UE comprising the CSI report for the beam wherein the CSI report is received according to the indication. 
 
 
     
     
       30. The apparatus of  claim 29 , wherein the indication comprises an uplink grant and the CSI report comprises a medium access control-control element (MAC-CE).